PFET based X-ray Detectors for the MIXS Focal Plane on BepiColombo

DEPFET Macropixel detectors, based oil the fusion of the combined Detector-Amplifier structure DEPFET with a silicon drift chamber (SDD) like drift ring structure, combine the excellent properties of the DEPFETs with the advantages of the drift detectors. As both device concepts rely oil the principle of sideways depletion, a device entrance window with excellent properties is obtained at full depletion of the detector volume. DEPFET based focal plane arrays have been proposed for the Focal Plane Detectors for the MIXS (Mercury Imaging X-ray Spectrometer) instrument oil BepiColombo, ESAs fifth cornerstone mission, with destination Mercury. MIXS uses a. lightweight Wolter Type 1 mirror system to focus fluorescent radiation front the Mercury surface on the FPA detector, which yields the, spatially resolved relative element abundance in Mercurys crust. In combination with the reference In formation from the Solar Intensity X-ray Spectrometer (SIRS), the element abundance can be measured quantitatively as well. The FPA needs to have in energy resolution better than 200 eV FWHM (c) 1 keV and is required to cover an energy range from 0.5 keV to 10 keV, for a. pixel size of 300 x 300 mu m(2). Main challenges for the instrument; are the increase in leakage current due to a high level of radiation damage, and the limited cooling resources due to the difficult; thermal environment in the mercury orbit. By applying ail advanced cooling concept, using all available cooling power for the detector itself and very high speed readout, the energy resolution requirement call be kepi; during the entire mission lifetime up to an end-of-life close of similar to 3 x 10(10) 10 MeV p / cm(2). The production of the first batch of flight devices has been finished at; the MPI semiconductor laboratory, and first; prototype modules have been built. The results of the first tests will be presented here.